1 //===----------------------------------------------------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is dual licensed under the MIT and the University of Illinois Open 6 // Source Licenses. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 // <memory> 11 12 // template <class Ptr> 13 // struct pointer_traits 14 // { 15 // typedef <details> difference_type; 16 // ... 17 // }; 18 19 #include <memory> 20 #include <type_traits> 21 22 struct A 23 { 24 typedef short element_type; 25 typedef char difference_type; 26 }; 27 28 struct B 29 { 30 typedef short element_type; 31 }; 32 33 template <class T> 34 struct C {}; 35 36 template <class T> 37 struct D 38 { 39 typedef char difference_type; 40 }; 41 42 int main() 43 { 44 static_assert((std::is_same<std::pointer_traits<A>::difference_type, char>::value), ""); 45 static_assert((std::is_same<std::pointer_traits<B>::difference_type, std::ptrdiff_t>::value), ""); 46 static_assert((std::is_same<std::pointer_traits<C<double> >::difference_type, std::ptrdiff_t>::value), ""); 47 static_assert((std::is_same<std::pointer_traits<D<int> >::difference_type, char>::value), ""); 48 } 49
